key concepts ++ enzyme activity

Question 1

describe the effect of temperature on enzyme activity

Answer 1

the rate of an enzyme-catalysed reaction increases as the temperature increases. However, at high temperatures the rate decreases again because the enzyme becomes denatured and can no longer function. As the temperature increases so does the rate of enzyme activity.

Question 2

describe the effect of substrate concentration on enzyme activity

Answer 2

Increasing substrate concentration also increases the rate of reaction to a certain point. Once all of the enzymes have bound, any substrate increase will have no effect on the rate of reaction, as the available enzyme

Question 3

describe the effect of pH on enzyme activity

Answer 3

At very acidic and alkaline pH values the shape of the enzyme is altered so that it is no longer complementary to its specific substrate. This effect can be permanent and irreversible and is called denaturation. Most other enzymes function within a working pH range of about pH 5-9 with neutral pH 7 being the optimum (most appropriate temp)

Question 4

explain what is meant by the optimum pH/temperature of an enzyme

Answer 4

The best or most appropriate - for instance, the conditions under which an enzyme works best (eg temperature and pH)

Question 5

how do u calculate enzyme activity

Answer 5

Enzyme activity = moles of substrate converted per unit time = rate × reaction volume (or read the damn graph)